The present invention relates to liquid drainage systems.
Before the present invention, an assortment of urine meters have been proposed to collect urine which drains through a catheter and drainage tube from a patient. The urine meters normally comprise a receptacle having a chamber to receive liquid from the drainage tube, and a container having a cavity. Provision is made for emptying the liquid from the receptacle chamber into the container cavity for retention therein. During the emptying procedure, a negative pressure is created in the receptacle chamber which impedes passage of liquid from the receptacle to the container. Thus, vents have been placed on the receptacle to permit passage of air from the atmosphere to the chamber in order to alleviate the negative pressure in the receptacle. Such vents have been provided with a filter in order to remove bacteria from the air which passes into the chamber, and thus prevent contamination of the system. However, during use of the device urine from the chamber may contact the receptacle filter, and it has been found that repeated contact by urine against the filter may cause closure of the filter. Thus, the vent on the receptacle may be rendered inoperative in that it no longer permits passage of air through the filter. As a result, a negative pressure is created in the receptacle when attempting to empty the receptacle into the container, thus preventing passage of liquid from the receptacle and also rendering the urine meter inoperative.